A drag, or harrow, needs to float over the ground, not have a heavy frame or ridged attachment.
One easy way to make a section on a 3 point is to get a 3pt boom arm, used for lifting 1000 lbs or so on a pole on the 3pt....
Attach the drag to the 3pt shaft of the boom pole with short chains.
Attach a longer chain from the end of the boom pole to the back of the drag section.
Lift the boom pole, and your drag section comes up.
Lower the boom pole, and the harrow is pulled by the short front chains, and allowed to float freely by the loose rear chains.
Take off the chains, and you still have the normal use of the boom pole.
Something like this, for example: